1. Field of the Invention
The present invention relates to a laminated heat exchanger with a single tank structure used mainly in air conditioning systems in motor vehicles.
2. Description of the Related Arts
Heat exchangers of this type in the prior art include a heat exchanger provided with tube elements which are each constituted with a tank portion formed by distension at one end in the direction of the length and a fin holding portion at the other end in the direction of the length formed by bending in which the tube elements are laminated to constitute tanks on one side of the heat exchanger core. The fin holding portions for holding fins are in contact on the opposite side from the tanks of the heat exchanger core. (Refer to, for instance, Japanese Examined Patent Publication No. H4-34080)
In this prior art, since the heat exchanger is structured to have the fin holding portions in contact on the opposite side from the tanks in the heat exchanger core, when brazing the heat exchanger, the brazing material tends to flow into the contact area and this causes a problem in that there may be insufficient brazing material in the other areas.
Because of this, in typical heat exchangers now, the fin holding portions are not put into contact with each other but instead are made to face each other with a gap of specific dimension between them.
However, with the type of heat exchanger in the prior art described above, in which the fin holding portions in adjacent tube elements are not in contact but are positioned facing opposite each other with a gap of specific dimension between them, a problem arises that, during assembly of the heat exchanger, fins tend to extend out of the gaps between the fin holding portions and to become pinched.
In addition, even when the heat exchanger is assembled without the fins extending out, the fins can still be pushed out due to misalignment of the core.
When fins become extended out of the gaps between the fin holding portions in this manner, difficulty in adding the lining may result and also problems such as lowered performance, running out of brazing material and the like may occur.